NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Earth Observing-1 Advanced Land Imager: Imaging Performance On-OrbitThis report analyzes the on-orbit imaging performance of the Advanced Land Imager (ALI) on the Earth Observing-1 satellite. The pre-flight calibrations are first summarized. The methods used to reconstruct and geometrically correct the image data from this push-broom sensor are described. The method used here does not refer to the position and attitude telemetry from the spacecraft. Rather, it is assumed that the image of the scene moves across the focal plane with a constant velocity, which can be ascertained from the image data itself. Next, an assortment of the images so reconstructed is presented. Color images sharpened with the 10-m panchromatic band data are shown, and the algorithm for producing them from the 30-m multispectral data is described. The approach taken for assessing spatial resolution is to compare the sharpness of features in the on-orbit image data with profiles predicted on the basis of the pre-flight calibrations. A large assortment of bridge profiles is analyzed, and very good fits to the predicted shapes are obtained. Lunar calibration scans are analyzed to examine the sharpness of the edge-spread function at the limb of the moon. The darkness of the space beyond the limb is better for this purpose than anything that could be simulated on the ground. From these scans, we find clear evidence of scattering in the optical system, as well as some weak ghost images. Scans of planets and stars are also analyzed. Stars are useful point sources of light at all wavelengths, and delineate the point-spread functions of the system. From a quarter-speed scan over the Pleiades, we find that the ALI can detect 6th magnitude stars. The quality of the reconstructed images verifies the capability of the ALI to produce Landsat-type multi spectral data. The signal-to-noise and panchromatic spatial resolution are considerably superior to those of the existing Landsat sensors. The spatial resolution is confirmed to be as good as it was designed to be.
Document ID
20040003964
Acquisition Source
Goddard Space Flight Center
Document Type
Other
Authors
Hearn, D. R.
Date Acquired
September 7, 2013
Publication Date
December 31, 2002
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
PR-EO-1-12
ESC-TR-2002-078
AD-A410322
Funding Number(s)
CONTRACT_GRANT: F19628-00-C-0002
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Keywords
ALI (ADVANCED LAND IMAGER)
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available